2000 Chrysler 300 NO Bus

My 17 year old son owns a 300M. Right after getting it we had to have a new flywheel and starter put on it. It was doing great. Then he decides that he's going to put in a new radio and speakers. He did this himself. He got a NO BUS error that he finally got to go away. The very next day while driving down the road it just quit and hasn't started back up since. It will crank but not start.
Last night he decides to take his radio out of his non running car and put it in my 2004 Jeep Liberty. He received a NO BUS error and the Jeep wouldn't start. He took the radio back out of the Jeep and it started fine (without replacing it with the old radio). So we thought while the radio was out of his own car we should try to start it. Again it cranked but would not start. Does the radio NO BUS error have anything to do with the fact that his car won't start? If so, how can we fix it?

Thank you.